Toward a Better Understanding of Adherence to Micronutrient Powders: Generating Theories to Guide Program Design and Evaluation Based on a Review of Published Results.

Background: The Global Alliance for Improved Nutrition is conducting theory-driven process evaluations of micronutrient powder (MNP) programs. Objective: The aim was to generate preliminary theories about factors affecting adherence to recommendations with regard to point-of-use fortification of foods with MNPs. Methods: A literature search was conducted to identify documents with content related to adherence to MNPs as an intervention provided at home to children 6-59 mo of age. Thirty-five studies and 6 program descriptions were identified. We used thematic analyses to generate a comprehensive list of factors that could influence adherence, followed by content analysis to quantify the results. We developed a Program Impact Pathway to concretize the points at which the factors identified affect the process of adherence. Results: In the set of documents reviewed (n = 41), the most influential factors, measured by number of documents reporting the factor having effect, were 1) caregivers' perception of positive changes as a result of MNP use (n = 14), 2) caregivers' perceived child acceptance of food with MNPs (n = 12), and 3) caregivers' forgetfulness (n = 11). Behavior change communication channels (n = 13) and messages (n = 12) were the most frequently reported program design features influencing caregiver knowledge and subsequent adherence. Administration regimen (n = 10), which may be related to caregivers' capacity to remember to give MNPs, was also a frequently cited program design feature affecting adherence. Conclusions: The preponderance of knowledge and perception factors may reflect an underlying theoretical bias among researchers as to what they measure. To achieve programs that support greater adherence, we need to adopt a cultural-ecological perspective to inform program design in order to address a broader set of determinants. Studies that assess progress across the impact pathway, particularly from adherence to biological outcomes, would also provide guidance for evaluation studies, particularly when time or other constraints limit the potential to measure biological outcomes.